line a 8" pie plate with foil.
Melt 1 cup of chocolate.
Pour into pie plate, swirl chocolate around to coat the sides, repeat so the sides are will coated, about 12 times.
Sprinkle first portion of hazelnuts onto the bottom of the pie plate so they stick into the chocolate.
Refrigerate about 10-15 minutes.
Warm caramel so it is pourable, pour on top of hazelnuts in pie plate.
Sprinkle top of caramel with second 1/2 of the hazelnuts.
Refrigerate about 20 minutes.
Melt remaining chocolate, pour over the caramel/hazelnut mixture. Using an offset spatula evenly spread the chocolate over the top making sure to spread it over the entire top.
Garnish as desired.
If sprinkling with sea salt wait until chocolate is set so it doesn't dissolve into the warm chocolate.
Let set in refrigerator, minimum 45 minutes.
When its time to cut into the bark heat a large chopping knife under hot water, dry it completely. It will help soften the chocolate as you cut into it. You may need to rewarm it a few times.
You can cut it in the pan or lift it out of the pan by the foil to make larger cuts.
If making for a party I would recommend cutting into pieces and placing into paper candy cups.